Ammonium removal from coking wastewater in a pilot-scale two-stage aerobic biofilm system: Biokinetic analysis
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- 作者：Xin Zhou ; Zeqian Zhang and Yaxin Li
- 刊名：The Canadian Journal of Chemical Engineering
- 出版年：2017
- 出版时间：March 2017
- 年：2017
- 卷：95
- 期：3
- 页码：432-439
- 全文大小：669K
- ISSN：1939-019X
文摘
A novel four-stage pilot-scale anaerobic/anoxic/oxic/oxic (A2/O2) biofilm process was successfully developed to treat coking wastewater with high ammonium loading. In this study, three different dynamical models including the first-order substrate removal model, the Monod-biological contact oxidation (Monod-BCO) model, and the modified Stover-Kincannon model were particularly applied to analyze kinetics of ammonium removal in a two-step aerobic stage. For the O1 reactor, all models were appropriate for describing ammonium removal and the correlation coefficients of first-order substrate removal model, BCO model, and modified Stover-Kincannon model were 0.8974, 0.9210, and 0.9726, respectively. The model verification indicated that the modified Stover-Kincannon model was slightly more applicable to predict ammonium removal in the O1 reactor. It was demonstrated that the maximum removal rate of ammonium was 0.208 kg/(m3 · d) by the Stover-Kincannon model. For the O2 reactor, the modified Stover-Kincannon model turned out to be the best fitting kinetic model for ammonium removal compared to the first-order substrate removal model (R2 = 0.1556) and Monod-BCO model (R2 = 0.5022). The maximum ammonium conversion rate (Um2-O2) by the modified Stover-Kincannon model was 1.180 kg/(m3 · d), while saturation rate constant k3-O2 was 1.221 kg/(m3 · d). Furthermore, the determination coefficient between measured and predicted values obtained by the modified Stover-Kincannon model was quite high (R2 = 0.9788) in the O2 process and a lower average residual square (6.60 × 10−6) was also obtained. The results of kinetic studies by the Stover-Kincannon model can predict ammonia removal efficiency well in two-step aerobic biofilm reactors of a coking wastewater treatment combined system.